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midpoint ellipse.py
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midpoint ellipse.py
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import numpy as np
import matplotlib.pyplot as plt
from PIL import Image
img = Image.fromarray(np.zeros((150, 150), dtype=np.float32), mode= "F")
def ellipse(major,minor, xcenter, ycenter):
x = 0
y = minor
p1 = minor**2 - (major**2 * minor) + (0.25 * major**2)
dx = 2 * minor**2 * x
dy = 2 * major**2 * y
img.putpixel((x+xcenter, y+ycenter), 3)
img.putpixel((-x+xcenter, y+ycenter), 3)
img.putpixel((x+xcenter, -y+ycenter), 3)
img.putpixel((-x+xcenter, -y+ycenter), 3)
# Region 1
while(dx < dy):
x += 1
if (p1 < 0):
dx = 2 * minor**2 * x
p1 = p1 + dx + minor**2
else:
y -= 1
dx = 2 * minor**2 * x
dy = 2 * major**2 * y
p1 = p1 + dx -dy + minor**2
img.putpixel((x+xcenter, y+ycenter), 3)
img.putpixel((-x+xcenter, y+ycenter), 3)
img.putpixel((x+xcenter, -y+ycenter), 3)
img.putpixel((-x+xcenter, -y+ycenter), 3)
# Region 2
p2 = (minor * (x + 0.5))**2 + (major * (y-1))**2 - (major * minor)**2
if(dx >= dy):
while(y>=0):
img.putpixel((x+xcenter, y+ycenter), 3)
y -= 1
if(p2>0):
dy = 2 * major**2 * y
p2 = p2 - dy + major**2
else:
x += 1
dy = 2 * major**2 * y
dx = 2 * minor**2 * x
p2 = p2 + dx - dy + major**2
img.putpixel((x+xcenter, y+ycenter), 3)
img.putpixel((-x+xcenter, y+ycenter), 3)
img.putpixel((x+xcenter, -y+ycenter), 3)
img.putpixel((-x+xcenter, -y+ycenter), 3)
ellipse(40,50,70,70)
ellipse(5,15,50,90)
ellipse(5,15,90,90)
ellipse(10,20,70,50)
plt.imshow(np.array(img))
plt.show()